Insight into the black hole currently characterizing the initial post arrest phase

Theresa M. Olasveengen – Jo Kramer-Johansen

As many emergency medical services are looking to further develop their resuscitation efforts to match emerging in-hospital possibilities for cardiac arrest victims, more unstable patients may be arriving at our hospitals. Percutaneous coronary intervention and extracorporal life support are increasingly being offered in the in-hospital environment to selected patients in cardiac arrest, and pre-hospital providers are consequently attempting to select patients in which underlying causes may be identified and treated. The «stay and play» mantra that has shaped many treatment strategies for out-of-hospital cardiac arrest is under scrutiny. With this aggressive approach we should expect increased transportation of arrested or severely unstable patients, and with that a greater need for monitoring and prehospital competence to safely deliver these patients to hospital. In the last issue of Resuscitation, Salcido and colleagues give us some preliminary insight into the largely ignored, yet critical time period from initial return of circulation to stabilization in intensive care unit.1

There are some earlier retrospective accounts of rearrest including previous work by the authors. While rearrest is reported to be uncommon (6%) in the setting of secondary transports by highly specialized teams,2 rearrest during primary transport to hospital has been reported to occur in somewhere between 5% and 40% of patients who regain spontaneous circulation out-of-hospital.3, 4, 5 The various registry data used for these estimates are all retrospective and rearrests are identified by different methods, making comparisons between systems impossible. More reliable prospective data is available from some of the clinical trials evaluating prehospital hypothermia suggesting rearrest rates between 20% and 30%, yet as they only include selected patients screened for study inclusion they too have limited generalizability.6, 7, 8

The study presented in the last issue of Resuscitation uses several methods to detect rearrest, all retrospective and all flawed.1 The variability observed between regions and systems in this current multi-center study mirrors the variability demonstrated in previous publications,3, 4, 5 and illustrates many of the problems that occur in attempts to compare retrospective data collected in different ways. Yet the sheer volume and persistence of significant rearrest events, even with the most conservative estimates underscores the clinical relevance of the rearrest issue and the importance of high quality post-resuscitation care from the moment circulation is restored. The timing of rearrest is also concerning as it was most often observed 4–7?min after return of circulation, during the time interval when transport is likely being initiated. Providing this metric allows us to reflect on which additional efforts could possibly be undertaken to best monitor and perhaps even prevent rearrest.

From a health care services point of view, rearrest events are difficult to interpret. Systems with a high percentage of rearrest among patients admitted to hospital after cardiac arrest could mean two completely different things. A high rearrest rate might mean the system treats cardiac arrest aggressively in the field and select unstable patients for transport to hospitals with further invasive treatment capabilities. On the other hand, rearrests could be preventable events occurring due to insufficient care after return of circulation. Nonetheless, many of these effects could be teased out by provision of uniform definitions, prospective data collection and population based incidence reporting.

So perhaps the «take home message» here is that most systems do not pay enough attention to what is going on after initial return of circulation, and are not likely to capture the data necessary to ensure that their prehospital providers are going the full distance in caring for cardiac arrest patients. Rearrest needs to be prospectively and systematically documented so that initial post-resuscitation treatment strategies for monitoring and circulatory and ventilatory support may be evaluated. Rearrest could very well be an essential quality parameter for emergency medical services looking to optimize their quality of care.

Conflict of interest statement

The authors declare no conflict of interest regarding this matter.

References

Salcido, D.D., Sundermann, M.L., Koller, A.C., and Menegazzi, J.J. Incidence and outcomes of rearrest following out-of-hospital cardiac arrest resuscitation. Resuscitation. 2014; 86: 19–24View in Article | Abstract | Full Text | Full Text PDF | Scopus (1)

Hartke, A., Mumma, B.E., Rittenberger, J.C., Callaway, C.W., and Guyette, F.X. Incidence of re-arrest and critical events during prolonged transport of post-cardiac arrest patients. Resuscitation. 2010; 81: 938–942View in Article | Abstract | Full Text | Full Text PDF | PubMed | Scopus (7)

Brooke Lerner, E., O’Connell, M., and Pirrallo, R.G. Rearrest after prehospital resuscitation. Prehosp Emerg Care.2011; 15: 50–54View in Article | CrossRef | PubMed

Salcido, D.D., Stephenson, A.M., Condle, J.P., Callaway, C.W., and Menegazzi, J.J. Incidence of rearrest after return of spontaneous circulation in out-of-hospital cardiac arrest. Prehosp Emerg Care. 2010; 14: 413–418View in Article | CrossRef | PubMed | Scopus (11)

Chestnut, J.M., Kuklinski, A.A., Stephens, S.W., and Wang, H.E. Cardiovascular collapse after return of spontaneous circulation in human out-of-hospital cardiopulmonary arrest. Emerg Med J. 2012; 29: 129–132View in Article | CrossRef | PubMed | Scopus (3)

Kim, F., Nichol, G., Maynard, C. et al. Effect of prehospital induction of mild hypothermia on survival and neurological status among adults with cardiac arrest: a randomized clinical trial. JAMA. 2014; 311: 45–52View in Article | CrossRef | PubMed | Scopus (57)

Kämäräinen, A., Virkkunen, I., Tenhunen, J., Yli-Hankala, A., and Silfvast, T. Induction of therapeutic hypothermia during prehospital CPR using ice-cold intravenous fluid. Resuscitation. 2008; 79: 205–211View in Article | Abstract | Full Text | Full Text PDF | PubMed | Scopus (40)

Kim, F., Olsufka, M., Longstreth, W.T. et al. Pilot randomized clinical trial of prehospital induction of mild hypothermia in out-of-hospital cardiac arrest patients with a rapid infusion of 4?°C normal saline. Circulation.2007; 115: 3064–3070View in Article | CrossRef | PubMed | Scopus (239)